RESUMO
The "fat hypothesis of coronary heart disease", according to which saturated fatty acids (SFA) increase the concentration of low-density lipoprotein-cholesterol (LDL-C) and consequently increase the risk for cardiovascular diseases, influenced the nutritional recommendations over the last 60 years, initially in the USA and later also in Europe. Over the years there accumulated a growing body of evidence from epidemiology and controlled clinical studies that the consumption of SFA per se was not associated with an increased cardiovascular risk and the limitation of consumption of SFA did not show a preventive effect. The focus on the SFA content negated the biologically heterogeneous and sometimes biologically favorable effects of various SFAs. In addition, it was neglected that SFAs in foodstuffs are bound in a variety of complex matrices, which are composed of dozens of nutrients with different structures and concomitant substances and therefore each triggers different biological responses and metabolic effects. Accordingly, such nutrient-based recommendations are principally not very productive and also difficult to realize. In addition, LDLC is not a suitable marker to assess the effect of lifestyle interventions, such as nutrition or physical activity, on the global cardiovascular risk.
Assuntos
Doenças Cardiovasculares , Ácidos Graxos , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , LDL-Colesterol , Gorduras na Dieta/metabolismo , Ácidos Graxos/metabolismo , Fatores de Risco de Doenças Cardíacas , Humanos , Fatores de RiscoRESUMO
Moderate alcohol consumption and in particular wine consumption, is associated with a significant reduction in cardiovascular morbidity and mortality in epidemiological studies. Although no randomized placebo-controlled studies with wine intervention exist - and will probably never exist - the observed association can be interpreted as causal due to the existing high biological plausibility. There is more and more evidence that ethanol per se contributes to the most relevant preventive effects. When consumed in moderation the health benefits outweigh the health risks. Whether and to what extend the numerous plant compounds of wine (polyphenolic substances) can provide additional health benefits is still under investigation.
Assuntos
Doença da Artéria Coronariana/terapia , Etanol/uso terapêutico , Medicina Baseada em Evidências , Vinho , HumanosAssuntos
Doença das Coronárias/etiologia , Gorduras na Dieta , Humanos , Masculino , Fatores de RiscoRESUMO
Three saturated fatty acids (C 12:0, C 14:0, C 16:0) raise LDL cholesterol but also HDL cholesterol levels. Replacement of these fatty acids by monounsaturated or omega-6 polyunsaturated fatty acids will lower LDL cholesterol as well as HDL cholesterol levels. Fat modified diets therefore may not improve the ratio of LDL to HDL cholesterol. Linoleic acid enhances sterol excretion but also increases cholesterol synthesis so that total body cholesterol is not diminished. Moreover various potentially adverse effects have been reported for n-6 polyunsaturated fatty acids. Recent cross-cultural ecologic studies as well as all major within-population cohort studies have not been able to find an association between cholesterol raising saturated fatty acids of animal fat and risk of Coronary Heart Disease (CDH). On the other hand several cohort and case control studies have shown an increase in CHD risk with increasing consumption of partly hydrogenated vegetable margarines. Meta-analyses of controlled intervention studies reveal that cholesterol lowering diets have failed to lower risk of CHD or total mortality. Yet controlled studies implementing a high level of antioxidants in the diet or increasing the n-3 unsaturated fatty acid content have been able to lower CHD and total mortality. It is time to discuss whether the concept of dietary intervention with the "classic" cholesterol lowering diet is still justified.